SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66c803db555759864e1d71b1f0f3d94b0931dc6baad492b1786d7f30f8e75ddb' 
  AND token = 'nK1iO1O0U741Diy7ORUkQPAHLTR6G36VuY5/4/93dX0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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