SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3e60cbb8591260987789f0983dde02b667689d3907fa4953874b42d3737e83d' 
  AND token = '+KplO7hm9HMr2X2n94pP70iBszUNxqtCZWgpZadtfIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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