SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5d20676f82e9dc4bd3d6f89a0c2fc90c5b429bc6113fc728dc672a7774ccf19' 
  AND token = '5rgh1Z+L3JxF0lrqhpG/7VU8vtu67P4rmc5R0/lQYvw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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