SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26d42b174ab6930abbc1a8c494203d91964be4d29b479c8c1779896046d8438e' 
  AND token = 'AVWLNE4UCMvhMifIcJA1hslHDm+PpAzaY4772w+/AMI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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