SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '65bb92a5c65f9b5c6e79b3f837c5cddd102cc87264364f6171017149998a3c12' 
  AND token = '+KObt00VYuZ1usoWQHFZOKuO/hqfhkVu1svSI4LwN0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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