SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '35043870d16a891ac5c6b3e33752ae2081fb65bce35af98cb8227feb7c5c3baa' 
  AND token = 'IagziBqv3MNoOIc6ZABjN2jbFU9yn9ZPnPcn9CiyuqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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