SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dbf9a7535766bb2cd674ad3fdf528373421a7a720a4934124408ca7d213d0be' 
  AND token = 'cXM+9yyYnUSZ5k3xbm3cLFf19zF8KRH/4NStRh54WJM=' 
  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"
    }
  }
}