SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c691bf2dd784f08fff991318ea7fa94c8ee42547057237869cd11f9c74b4f32' 
  AND token = 'XC7ERza5Vbx7uOSPvqmxP11io9e+mQur+knkJvgHTMU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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