SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9a0cb0f9a28ce1909abddf75fdb8f6884c361aa20aaa8743d01e43b467ab6ba' 
  AND token = 'PnXSJuFtU6W0TePENK9usghb+A8SFsibSrY8+fGaxEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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