SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f10714a9358099847259ab76401613c2dcc2e03ecacf8557f7b17c9071cc83af' 
  AND token = 'cXS+jEuhR4OW2FBzyZp7VbT12VuKHgKhmGhuRX7aeTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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