SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1952ff98e25003a7a6cf26236669fa573bee3a20d478edf6ce487ebc06cc747a' 
  AND token = 'pfaj1UfCfNU/cpbuh0RB+3vt0OpSF3r8rNzFxWT8Q/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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