SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75348a73b1d45b8dc49ed0fe883ed5726b23772164074d90f7fb1adb2c0fe836' 
  AND token = 'dxEfKbBgtSwv34ZgfvjLswlhPz7dusPGlQZpGGLYB24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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