SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80becc5c0a85856a57ba1176f38e74b8316d9f3759537509941d4e5528415085' 
  AND token = '4NV589gEBk61nJrIHps4swu+z91Iy3AQQSlkUwfcpZk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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