SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f25a48d007dc4d697d63e93660f37e7734af487ba9ce3436521b31904e1eb9ca' 
  AND token = '8P3F/7WFhomJ6YF1UJllFyLRsAccnNaHRiLnsIozJPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}