SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4103fc81ded6b80e69887c758222a4326a5a0714776f7f4f0ae14640f2bb1e93' 
  AND token = 'cHwnNcCDbxzmWGFwc/XLBVE5ej4QrGqodi0odpPZZFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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