SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65af9ec0b91b3975cc445cf156b22cc46e30e95e77f5a5f84bbe33c19e1b51e9' 
  AND token = '0mF/oPrsaZIjW8mniCJp55TAxmzRpPUj0RUfY4y6aqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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