SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20dedab0e6a1b5e52c206aadfaf2fa515525885b6470af53a9ac3cf3a45729cf' 
  AND token = 'ZjZLTxRvcetpGv7me7GTWmlNpAaOGlzRQ0JWavZoTdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}