SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdd22f4891cb3dbf0798d0c6e256f7d7b2d31c4ece98272fb661d15cb37252aa' 
  AND token = 'MY5rveE1O3Fds1q35bafO/4tQVrhZxGw/87314/5cgE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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