SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efbbb22edcd925f2318a7d0deac4375672cee03d9d7bcc9909282fda14279261' 
  AND token = 'iCtfTAT3tZHwpfzEcU0ywhOVmrbDcfly5BS3+eAmgXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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