SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4c79d14b164c02f6f7c58fbfd02681bff12131a2596e502c7435169b800c2e6b' 
  AND token = 'ckL9EiSuWps/4NfLrNa+LmvaXow1CnwSUAtXImH1dJE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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