SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7abdc64042315ead7ac08397e609206ebedcaccaae2431bb6c1e712dc542de75' 
  AND token = 'fdNepFtyDV378AXQmzYHS9535MVFtdQriGvQly6Zbhc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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