SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e447cab42bc058f27dc0ea6163de2c644eddfb0ce6de6c73ad445aa7d5211bc2' 
  AND token = '9hoB1LPyxLpcIMgot7njHJ389R/dNhZPEKYnxcOi9RI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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