SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7cf18e6458f5c44363726229def2cffbd78403915ecb63f71319a7a8d2918440' 
  AND token = '3LSK1vgDWJg8dhjhZhw/XLTV+JCThV7fXDCTMdc6Gw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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