SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1999e85dd732d045615805682c54f5b913bd9434e507d5e8f76f5134a454c3e0' 
  AND token = 'ehFD9SSPAVCwnwFFihK4SDcXTpwDFClmT+5AKMWWyhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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