SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab2ed785468f1353f4a99c754a163f2eab0ec0d26d853d896b4a675770067328' 
  AND token = 'miNFDo5v3p2uNqEnSiqhYn158F/+pHPLDKBlJ358qUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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