SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'de432ca1c1e2867bb2cf8bb0fbdc6bc38eb6c84bcfee8d14b46d0742cb38d87e' 
  AND token = 'QI6xJUwA4Z5baaqCxAwOmCVwgsmm3gUkqox2kWHdREo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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