SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b72d52446de59dfbcd7dced2eea6a6367c8768fbc86ee96be6b3c80abe8652a5' 
  AND token = '2KOJNt1EJgFeY/Rlg8wdSTEIwpf3056jdwYaKkgQLZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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