SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd99592afdbd989c9a6406ba8da3e8812a93576b706a5b79156bc9718f0786978' 
  AND token = 'a0ktm6HO5EqLT9S9ZycvoTA2g8gkKqX1MVOzY1skfgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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