SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6b82e6e5bfe04de5c62e70d981b3345f7e5ead9f894ae59e56a1fb593e5ef04' 
  AND token = 'izlGZit9jAyN6PKimfV6+vUQTmpwj4fiTt2SRFwCYLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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