SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8067935e28709006325702fbce4a6c6bd64bb93b37db0d0a5604784645d0585' 
  AND token = 'PWj0EJgs7waBBr+mvPU4n0jWjSLpsJ9ox2CLNieJkFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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