SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7dd62dbaca88c4abdc803a01011e6f5939df5f2a5a477f865b5f047c9194ea45' 
  AND token = 'zV5noQjDOwGbLzXuu7BkCNJbT1edlpA8Zww+fJvjtdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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