SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af27f3b4e294299748c24a711f08cedc668606b8437729c994842a8be724d5ba' 
  AND token = 'Uq5+aqC7n05eTWjdAB/gYmjTHV2h6GV5TnrlFPOFGNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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