SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f6885ab83b7b0a3407daa683a1b9a8e669e413abcb937d15ce764f03caad522' 
  AND token = 'B0FUHs7jbksDJQwcxXv6x0T1AZ6aJklcXOkJ47hVYTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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