SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b451d333021a2f46580b16b20ddffd34845475d6ab9efbcb1cd5a4fd03688fb7' 
  AND token = '8XINIoKruciMsH01jT2GhWA7Th6YwCvRoLXnLRjOyXs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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