SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5cc5c21785ad0cca45f3e654e9635710f1e88a07102caba377e3646af1e645e6' 
  AND token = '21R0FhHqPgBvRFLu2AOGNbjFwk4ahBx9iX/5qyazD/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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