SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d1fc1cf6163c9ac6d00ffd42081cbe44132c4c1cdd1f7c62f4e8dbec61c276e' 
  AND token = 'JWpDEnmJ42McLEj0bzgUnESVlYLyct3ru5gmnqJUb24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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