SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d3203089919f3c9a7190db470c501f9bac42fbfc4fdaeb0eb9045b0f26ebca5' 
  AND token = 'CHuXo+TvPNaQ7658CzdvQr2nwYUNh2tjsY8L9KpQBo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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