SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6ba230f4144f2b023f6a7134447e4948964ad6140c7e93d5fdf2155a8b979ee' 
  AND token = 'ufWnkAwabQuJAFclUv2EX0SudPyZMGzUomExyrfFblg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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