SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9377fa694f41a037640394e15f9a5268712b5153c953bf5cf521a3b877911c0c' 
  AND token = 'stRHkethPwTFsa86fqsLBatCIvvpswrRmLm3ow1VO0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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