SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c3a066bfdeb3b1c7f85da97480d5496154ba7548e75634a2ef6aa1006060185' 
  AND token = 'CzAonOSfpQWH5a7SGSt0mD5nGImt7C+scMiMxAic5sY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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