SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbd0be05b5d0dfc0077e783b3415c6ebe2808cd19c1bc95714083aa55bd17c36' 
  AND token = '8DZ3EiZe4WBTwyK1N/5qlXezh5aJnQJKD7lFOdbFgp8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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