SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14757d76932821ffefdb900d3007f0ab678294cf3d94cbf0530a5d24ada29a82' 
  AND token = 'whJPmvNI1NLALJsENSozG8CbsoBmCZZoPSUEId3AmPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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