SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c49a62c2061cf60d53de54beb364c33105cf7b09e48dc3a1f24afedce27b9e7' 
  AND token = 'bCroJS9b+ref6dJcn+6cmySnlgeYtDqVjtAFBofmdCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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