SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd07e3f2c469f4320aec8a8ee38a931ba9f78cb36a706f1c65336006a01cdb53d' 
  AND token = 'irQdYMFm3HTmYwIhlwzn5QB//+3fZHXfD1RvnglsJj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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