SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e677416e603c414f410c2746331847e084da6352df6d9e4e7f3cf5aba67593b' 
  AND token = 'kECKZkrlN1KU8x3Tiz1qli4jhI01PaxOMlGnno9cE74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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