SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5772cfa546bcda74ab0ae39c193ee9255cea9cf7ed3904828e3a0079a95acf87' 
  AND token = 'eRcxcSsEyQWsjnyx5J2cFE+2g5jQF8GdULH9Lo54XeM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}