SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2536ccc0d669f9a3918a2d334909a86476813f85a51f4a83675454895212475' 
  AND token = 'dt1T0SMCNtco577ZwXbgBRPbbQYriH7WQhS7QiiHroU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}