SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de15187883ca5ac9d51d30bf2cf2f8084e291775827fb788bd35cfbf84bc96e8' 
  AND token = '5qfHrjYNWF/pg3M9vngw8BauRrTRjpFPwR0vBqyBvg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}