SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12111e838d3736667767fd97f085e85096e409fc54e306302ecdbb47a5c4ce3b' 
  AND token = 'AMgsNpfuoZYDYEwXIUX3a/HfydPaJBBSdzgJ/09C4GY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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