SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd2df1de1d4e64e3e1c29bd7e3caf535c92e9af774ad2fe281991d571c884fbb0' 
  AND token = 'gi/3kS5ByVNGeJekmSL+Ugpmq/h5ua95X2XGlx0q8vQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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