SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b28b542e089962993fcf350b8da2bc7adeabeab39545b62919e8b940bb6f4a81' 
  AND token = 'SMsEOtinGJ16B25jYgBqXIv7b+ezGKWfI98O6401kEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}