SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db033a187cde2431bcd3160217b3a1c7b992c3b8e7c5d8bda1db53e55df33ec8' 
  AND token = 'kHhjcgu3HRsVYiZLrxNdpwZGT/qW7c1ml8yC7SxrasY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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