SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60761afc7e31221fc06d3512ebcf354ad620bb7ff6cbba253894d25b0352fce7' 
  AND token = 'ofCBPxCO9ZksHU+b+mgzrZegNLRFWfAs1uE688WQkMs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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