SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '235b30f914c2da3e4fd773127ef094da88b53b27bba732d62b585af505fe5740' 
  AND token = '6Pz/nSPLmBpSOCHofDcuV7/pxuk200sWiep/QtJgsUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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