SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a379f8ff0fc7faa52107ff250cbf9b433c26f6a0ec87ff0f378344c3b879eb5e' 
  AND token = 'fT7mvsL4yKMjiZTRcgIlw1fEk5iw7smt3zibqevHEGY=' 
  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"
    }
  }
}