SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82659bf555c9e595e9a90e492cd90595a479e4b34185b15a2090c6dafa96711b' 
  AND token = 'sbJTuFIJdeEApUu5ijSumCKwP/MOWu1qG9UIl0S8Tcg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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