SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '306622b4ca70b37fe5b316188e300076a72b0f200ee7babf687559439a5e9fab' 
  AND token = 'moRqcOZ6V5QPQpVSP+YCkppEE8N6PYDY3e+ZQR4hai0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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