SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0a328cec0e7250e5e64ec53bb2e2cca2f29d4919b33729444ac8ad30666c537' 
  AND token = 'SdZ6kOtZfQJV8oqLb93J6a5WEFyvANkEjUUbAWlLSyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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